1. Field of the Invention
This invention relates, generally, to containers having lids. More particularly, it relates to containers that provide a visual indication to an ultimate consumer as to whether or not the container has been opened subsequent to its shipment from a packing facility.
2. Description of the Prior Art
Strawberries, blueberries, and other such fruits are commonly packed in clear plastic containers having hingedly attached or removable lids. Brussel sprouts, grape or cherry tomatoes and the like may also be sold in such containers. The containers are also suitable for nuts, trail mixes or deli items such as potato salads and the like. The containers are generally of parallelepiped construction and usually have rounded or beveled corners.
As a general rule, the lid is held in a closed position by a press fit within the rim of the container. The resulting friction prevents the lid from easily opening during container handling at the packaging facility, transporting of the filled container to its destination, and container handling at the grocery store. The consumer must intentionally exert a separation force in order to open the container, i.e., it will not open inadvertently.
However, grocery store customers have been observed opening such containers prior to purchase, taking a few (or more) morsels therefrom, and re-closing the lid. Such customers then purchase an unopened container or leave the scene of the pilfering with no purchase made.
Accordingly, the container industry has developed several container structures that indicate whether or not a container has been opened after its initial filling and closing.
One such structure includes a tab having a bottom half secured to the container base and a top half secured to the container lid. The top half is bordered by perforations so that it separates from the lid when the lid is rotated about its hinge to open the container. This creates a tab-shaped recess in the lid and indicates that the lid has been opened.
The problem with this design is that the recess is best seen when the container is open and if the container is open, no recess formed in the lid is needed to indicate that the lid has been opened. The pilferer simply re-closes the lid and the tab re-aligns with the recess. It requires careful inspection to determine whether or not the perforations that border the tab have been ruptured and most consumers do not perform such careful inspections.
Another design includes a tab that interconnects the base and the lid of the container so that a removed tab indicates that the container has been opened. The primary problem with that design is that an experienced pilferer can leave the tab in place and pry the lid open; the tab remains in place when the pilfering is completed and the lid is re-closed.
Thus there is a need for a tamper-indicating structure that is obvious even to a casual purchaser if the container has been opened and which makes it exceedingly difficult to open the container without removing a tab.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art how the needed structure could be provided.